Known coffee machines generally comprise a cap intended to receive a capsule containing a dose of the drink to be infused. The cap is taken, manually or automatically, to a percolating head comprising a bored needle, which allows the injection of water and/or of steam into the capsule.
One of the disadvantages of the existing machines is the fact that it is not possible to adapt the concentration of the drink prepared as the capsules all contain the same dose of the product to be infused. The only parameter which the user can vary is the quantity of water injected into the capsule. Thus, if the user desires a concentrated drink in a cup of large capacity, he will have to use two capsules of product in succession in order to obtain the desired concentration.